This invention relates generally to a process for making a package in a form/fill system, such as a vertical form/fill/seal (VFFS) system using either transverse seals or clips. The film, and the final package, preferably have a trap print feature.
It is common practice in packaging many goods, including food items, to use what is generally known as form-fill-seal equipment. In the vertical form-fill-seal arrangement, flexible packaging material is fed from a rollstock to a tube former where a tube is fashioned from the sheet material into a vertically dependent, upwardly open tube having overlapping longitudinal edges. These overlapping edges are subsequently sealed together longitudinally by means well known in the art, and the lower end of the tube is closed by a transverse heat seal, or by a metal clip. At this point the tube is filled with a quantity of the product to be packaged. This product can be e.g. a meat emulsion. A second transverse heat sealing or clipping operation, typically performed after the filled tube has been downwardly advanced, completes enclosure of the product. Simultaneously with or shortly after the second transverse heat sealing or clipping step the tube is completely transversely severed by known cutting means. Thereafter the tube is downwardly advanced and the cycle is successively repeated so as to form a multiplicity of individually packaged products.
Horizontal form-fill-seal equipment is also commonly used in many packaging applications.
Manufacturers of form-fill-seal equipment include Hayssen, Omori, Ilapak, and Kartridge Pak. The latter is used to make a clipped pouch.
Flexible packaging material useful for this as well as other applications typically must meet stringent requirements imposed by the particular food or other article to be packaged. These requirements often include limited oxygen transmission, dimensional stability, and abuse resistance.
Yet another requirement of packaging material, especially in form-fill-seal systems, is good heat sealability with respect to the longitudinal and transverse (if present) heat seals, which are sometimes subjected to loading forces from the introduced product such as food product, soon after the heat seal is formed.
In preparing a chub package of sausage or other processed meats or foods, it is often desirable to make a package that is printed to indicate brand names, product identification, and other information. These packages are sometimes filled at elevated product temperatures, and sometimes undergo a cooking step after packaging. These and other requirements for chub and other packages have traditionally been met by the use of certain conventional trap printed laminate materials. However, these materials tend to be expensive to produce, and it would be desirable to create a process where films such as coextruded films can be printed and then processed in a VFFS arrangement to produce a food package, such as a chub package, meeting the requirements of the customer and the marketplace.
The process described herein is useful in producing food packages, and especially packages having a print feature in the packaging material.